The study asked whether the respondent's country should be willing to use military force if Russia were to attack the following list of NATO member countries: Croatia, France, Germany, Greece, Latvia, Poland, Romania, Turkey, the UK and the US.
Respondents were also asked about non-alliance members Finland, Sweden and Ukraine, who could be Russian targets in the event of an attack.
As well as being unwilling to defend the US, the study suggested Germany would be unlikely to defend Ukraine, Romania and Turkey.
France would also be unwilling to defend the latter three nations, according to YouGov.
The publics of Germany, France and US were all more willing to defend the UK than not in the event of a Russian attack.
Turkey, despite its NATO status, seemed to be the country most were most reluctant to defend.
The US was in favour of defending Turkey, while Britons were split with a 31% to 31% divide as to whether they would defend them, with both Germany and France opposed defending them by a big margin.
It was also the German and French public who were not in favour of defending Ukraine or Romania either.
The US was also not gaining the support of Germany, as they objected to defending the US, whereas the US public thinks they should defend Germany should it find itself under attack.